Electronic power systems can include a power factor corrector (PFC) or a flyback convertor that uses PWM to regulate the power supplied to one or more devices. For example, a power system can include a controller that provides a PWM signal to command a switch (e.g., a power transistor) of a PFC, which in turn, controls the charging of a coil of the PFC. The controller can use an analog-to-digital converter (ADC) to sample the output voltage of the PFC to adjust the pulse length of the PWM signal to regulate the output of the PFC.